Utilizes assertIn - tests/api/v3

Using assertTrue and the 'in' operator to test
if an element is in a sequence is too python2.4.
Our unit testing framework supports assertIn,
which was created for these types of tests.
Using assertIn will enhance readability of the test scripts.

Change-Id: Ic3ae0a0eca219bd7d114580ad3642e7df04ad1f4
Merge "Utilizes assertIn - tests/api/v3"